Linux 6.12 Adding HDMI CEC Driver For A 4K HDMI Splitter/Amplifier

The media subsystem updates were submitted today for the Linux 6.12 kernel merge window. Notable this cycle is a new HDMI CEC driver for a 4K HDMI splitter/amplifier for those looking for a device that can be controlled from within Linux using the HDMI Consumer Electronics Control (CEC) specification.

HDMI CEC is the standard for controlling HDMI-connected devices and commonly for home TV setups is used so one remote can control multiple HDMI-connected devices. HDMI CEC is also marketed by a number of different vendor trade names. Linux has supported HDMI CEC with varying hardware devices for controlling the HDMI devices from Linux. Now with Linux 6.12 is a driver for the Extron DA HD 4K Plus HDMI Splitter.

The Extron DA HD 4K PLUS Series devices support 4K/60 @ 4:4:4< supports HDMI 2.0b, can handle HDCP 2.3 compliant content, and there are various for two, four, and six HDMI outputs. These are high-end HDMI amplifiers/splitters that can retail for more than one thousand USD.

The patch series introducing the new Extron DA HD 4K Plus HDMI Splitter driver explains:

"This driver adds support for this device, allowing full control of the CEC functionality (each HDMI input or output has its own /dev/cecX device) and EDIDs (each HDMI input or output has its own /dev/videoX device).

By using module options you can configure the driver to be fully transparent, i.e. it will pass on CEC messages between input and outputs and automatically configure EDIDs based on the detected displays, or leave it in manual mode, requiring userspace to configure everything manually."

This driver is part of the media subsystem pull request for Linux 6.12 that also contains a number of driver fixes and code clean-ups.